The search for the perfect ski

In its quest to optimise ski performance and design by integrating high-quality materials, zai has embarked on a scientific journey with the Institute of Materials Technology and Plastics Processing (IWK) of the Eastern Switzerland University of Applied Sciences. Innosuisse supports the project. Together, zai and the IWK are scientifically researching the parameters that determine the riding performance of alpine skis. Head of Test Material Technology at IWK, Dominik Stapf,  is in the lead of this collaboration and is himself a passionate touring skier. Together with zai CEO Benedikt Germanier, he explains in the interview what exactly they do in this joint project.

Benedikt, what led you to team up with the IWK?
Benedikt: For me, it is crucial to systematically understand what we do. With the IWK, we have the opportunity to systematically research how the performance of skis can be measured holistically. In our search for measurable components that determine the perfect ski, we chose to explore the damping properties of different materials and material composites as our first step. Damping is one of the parameters that influence a ski’s handling characteristics. Measuring the damping of different materials and material composites allows us to base the choice of materials for our skis on facts rather than gut feeling. With IWK, we have a partner in material expertise that helps us go beyond intuition and measure progress. Dominik is an interlocutor for me with whom I can play ideas back and forth. At the same time, we are keen to collaborate with a Swiss institution with young students to provide them with a real-world research task.

Dominik, is the development of skis and the collaboration with zai exciting for the IWK?
Dominik: The subject of skis is exciting and polarising. Up to now, there has been put relatively little scientific research into ski development. As an institute, it is interesting that we can participate in the development of projects from different areas. Of course, we can also further develop together with the industry partner while incorporating interdisciplinary experience. It is in our interest to support a Swiss company in realising its innovations and improving its market position. From the institute’s point of view, the project is interesting because we create an inspiring environment for our students through the industry and the projects. They can work on projects that have a genuine product and an industry partner at their core.

Benedikt, how do you measure the performance of a ski scientifically since it depends on so many influencing factors?
Benedikt: A good ski helps skiers be free on the ski and be able to do what they want. We take a holistic approach; we want to measure skiing performance holistically. To do this, we have tried to trace it back to measurable components and parameters. Skiing is technically losing altitude. As soon as speed comes into play, the material must not oscillate. Damping is responsible for this. It influences the smoothness of the ski and gives the skier comfort and safety. We expect these two main factors from a ski because you can only enjoy speed when it is controllable, and you feel safe and comfortable. That is why, for the time being, we decided to research the damping properties of different materials and material composites. Of course, it is not correct to claim that its damping properties solely determine the performance of a ski. However, it is an essential component and to know it in the composite – and not only of individual material components – is exciting.

Dominik, what exactly do you do at IWK, and with what goal?
Dominik: We implement technical solutions from the industry – resulting in a knowledge transfer. We have built a test stand to measure the damping of various materials, test objects, and even entire skis. We use it to test different surfaces, such as new types of stone, to determine the properties of a material or different material composites. The measurements are very reliable, but the parameters we measure are mainly subjectively noticeable when skiing. Damping is perceived differently by each person when skiing. All skiers react individually to a ski. The challenge is, therefore, to connect subjective impressions with the measured values of the test stand.

What is damping, and why is it a relevant factor for the riding characteristics of a ski?
Dominik: Damping is the speed at which the oscillation of an object decreases. The faster the oscillation of a ski decreases, the safer the ski feels. A ski has optimum damping characteristics when it vibrates quickly – i.e. is flexible – but at the same time quickly returns to its original state. Therefore, damping is sometimes at odds with agility. The material itself, the composite of materials, and the camber of the ski influence its damping characteristics.

How do you correlate the measured values of the test stand with the subjective impressions?
Dominik: The three of us spent a day testing all the models we had previously measured on the slopes to compare the measured values with individual perceptions. I had prepared questionnaires for each ski model to evaluate it independently with specific parameters such as comfort, how easy the ski is to ride, how the turn initiation works, or whether the ski seems fluttery or smooth. The idea was then to compare these results with the measurements. For the individual evaluation, we had hidden the measurement results in order to be uninfluenced. I didn’t expect the evaluations of the three test persons to be so different. There were only three of us, so the lot size was not scientific. For that, we would have had to be well into double digits, but that isn’t easy to realise. On the one hand, the ski doesn’t stay the same over its lifetime; on the other hand, skiing conditions are relevant, constantly changing.

However, it was exciting to see that three people gave such different ratings for each ski. At the same time, there were also clear parallels, which again makes it clear how complex the matter is. Everyone also has unique ideas about a ski, which influences the rating. For example, Benedikt is a ski instructor, David is a freerider, and I am primarily a touring skier. As a result, everyone has a different idea of the perfect ski. Especially when it comes to the performance and comfort of skiing, there were many identical ratings. But not everyone liked every ski equally. However, we also compared the measurements and perceptions of zai skis with a ski from the industry and found that the materials zai uses make a big difference.

zai has a ski made of stone. That’s extraordinary. Is stone the optimal material in terms of damping?
Benedikt: We have had excellent experiences with stone so far. Stone is a living material. We work primarily with metamorphic rock, which has been deformed for over 50 million years. For our zai stone, we use stone from a company in Graubünden, which extracts the stone from the rock. The stone is very workable, oily, and porous. Furthermore, due to its porosity and damping properties, the stone is not heavier than aluminium, which positively impacts the performance. We are practically converting the mountain into a ski.

What other materials have you tested so far, and how do you go about selecting materials?
Benedikt: The material has to fit into the design concept, be sustainable, and meet the customer’s needs. We have already tried out various materials such as natural rubber, stone, cellulose or cork. So far, we have found advantages and disadvantages in each material. Carbon, for example, we liked because of its lightness and simultaneous rigidity. Rubber dampens well but is very heavy. Damping is always measured in relation to weight. Advantages of rubber are others, such as being aesthetic, easy to work with, and very sustainable.

Dominik, to what extent does the project with zai contribute to sustainability in ski construction?
Dominik: We develop prototypes and focus on the development of a sustainable ski concept. With the test stand, we created a machine that allows us to keep becoming faster and more efficient, so it will no longer be necessary to develop too many prototypes.

Benedikt, what does sustainability mean to zai, and how is it integrated into a zai ski?
Benedikt: Various factors influence the sustainability of a product. In recent years, we have optimised our components primarily in terms of performance. Over time, we have acquired a new awareness and are also focusing on optimising sustainability. Particularly in the sports sector, there is also an expectation from the customer side that the company should address sustainability and take responsibility. Companies try to substitute previously used materials with natural materials, which can be a challenge when achieving the same conditions and results. We claim that the same performance can be achieved with a smaller environmental footprint through the smart use of materials. We are a company that produces something and thus, as a consequence, pollutes the environment. But we strive for the optimum in all respects. For example, our internal life cycle assessment showed that travel and the thousands of car kilometres it involves are dominant in energy use. In production, we concentrate on the manufacturing of long-lasting goods. These can be reworked and refreshed. By being able to test materials, we can compare products over their life cycle. We care about the longevity of our skis because longevity is a key factor in sustainability.

Do you already see any success in what you have done together so far?
Benedikt: We have a reliable, measurable system that allows us to get better. We can transfer technology into our products and make surfaces more and more sustainable. Since a ski is also a living product that changes over its lifetime, it takes at least 2-3 winters to make accurate statements. Therefore, the ski must be exposed to the conditions over a longer period.

What benefits do ski enthusiasts derive from your research?
Benedikt: Whoever buys zai also buys an attitude to life. Building durable products is an essential part of this; skiing performance and sustainability are not at odds. Moreover, we do not just want to meet our customers’ demands, we want to exceed them. It is our way to move forward transparently, comprehensibly, and responsibly, always one step ahead. We want to innovate and implement without claiming to be representative. We are not afraid of being copied. We are looking to optimise performance and design by integrating high-quality materials. We do not want to be secretive; we want to encourage open innovation. Furthermore, we want to motivate others to collaborate with institutes and explore further avenues.

About the project

Zai EcoSwiss – Conception and validation of a novel ski test stand for data-based “first-time-right” design of sustainable high-performance alpine skis.

Innosuisse – Swiss Innovation Agency, supports the project. The aim is to develop sustainable high-performance alpine skis with optimised oscillation behavior through innovative structures and optimal use of the material properties of renewable raw materials. The basis for the characterisation and optimisation of the skis is the development of a specific test stand.

About the Institute of Materials Technology and Plastics Processing (Institut für Werkstofftechnik und Kunststoffverarbeitung IWK)

IWK combines science and praxis for innovative solutions with modern materials, processes, and multi-material technology.

The Institute of Materials Technology and Plastics Processing (IWK) is an institute of the Eastern Switzerland University of Applied Sciences located in Rapperswil, Switzerland. Since 2005, the IWK has been committed to education and training, applied research and development, technology transfer, and services for external clients. In the IWK team, experienced specialists and experts work together with young university graduates in an uncomplicated, professional, and project-oriented way on tasks from the industry and publicly funded research projects. They are also involved in education and training in vocational and higher education.

The IWK maintains project-related cooperation with partners from industry and universities in the regional and supra-regional area.